This application claims the priority of Japanese Patent Application No. 3-106020 filed May 10, 1991 which is incorporated herein by reference.
1. Field of the Invention PA1 2. Description of the Related Art
The present invention relates to swash plate type compressors. More particularly, the invention relates to an improved swash plate type compressor for use in vehicles.
The Japanese Unexamined Utility Model Publication No. 54-55711 discloses a swash plate type compressor which has a front and rear housing sections, and a front and rear cylinder blocks. A central section connects the front and rear cylinder blocks, and includes a swash plate chamber which is fluidly connected to a refrigerant suction port. Each cylinder block has a distal end which is covered by the front and rear housing sections. A front valve plate is disposed intermediate the front cylinder block and the front housing section. Similarly, a rear valve plate is disposed intermediate the rear cylinder block and the rear housing section.
Each housing section includes a suction chamber and a discharge chamber. The discharge chamber leads to the refrigerant discharge port. A drive shaft is rotatably supported by the cylinder blocks, and is connected to a swash plate located inside a crank case.
Each cylinder block has a plurality of refrigerant suction passages to drive the refrigerant from the crank case to a suction chamber in the housing sections. Each cylinder block also includes a discharge passage which connects a discharge chamber in the front housing to a discharge chamber in the rear housing. The discharge passage is generally disposed concentrically around the outer periphery of the suction passages. A ring shaped lip seal is arranged coaxially with the drive shaft, within the suction chamber, in order to provide an airtight seal around a portion of the drive shaft, so as to prevent refrigerant in the suction chamber from leaking.
When the drive shaft rotates, it frictionally engages the lip seal. Thus, lengthy usage of the compressor subjects the lip seal to significant wear and thermal deformation.
Furthermore, the suction passage is disposed at a relatively remote location from the suction chamber. This causes some irregularity in the distribution of the refrigerant in the suction chamber, and results in a generally non uniform concentration of the refrigerant in the suction chamber.